Processes and apparatus for feeding material to a glass melting tank

Apparatus for feeding material to a glass melting tank comprising, a first feed means for feeding solid batch material to the tank at an adjustable and controlled rate, a second feed means for feeding cullet to the tank at an adjustable and controlled rate, a first control means for controlling the rate of feed of the solid batch material in said first feed means, a second control means for controlling the rate of feed of cullet in said second feed means, a glass level detector for detecting the level of glass within the tank and generating a first control signal indicative of said level, one of said control means being arranged to receive said first control signal and thereby control the feed rate of the associated feed means in dependence on the level detected, and an adjustable ratio control unit arranged to receive a signal dependent on the rate of feed of said associated feed means and provide a second control signal to the other of said control means such that the first and second control signals correspond and maintain a predetermined ratio of feed rates for the two feed systems.